Fluid pump



I Feb. 25, 1941. G, A, W LMAR 2,232,983

' FLUID PUMP v Filed June 8, 1958 3 Sheets-Sheet 1 INVENTOR.

ATTORNEY.

Feb. 25, 1941 G. A. WAHLMARK FLUID PUMP 3 Sheets-Sheet 3 Filed June 8, 1958 PATENT oFFicE' Application June 8, 1938, Serial No. 212,475 10 Claims. (iUl. Juli-i2) The invention relates more particularly to a closed but aim to cover all modifications and unitary pump and the valve device for supplying alternative constructions falling within the spirit fluid under pressure to oil burners. and scope of the invention as expressed in the It is a general object of the invention to proappended claims. vide a new and improved. fuel pumping and con- In the forms chosen for purposes of disclosure, 5 trol unit of this character. the invention comprises generally a two-part Another object is to provide a fuel pumping casing 20, 20', a pumping device or means H, a unit embodying the pumping elements so ardrive shaft 22, a mechanical seal 23 for the drive ranged that by removing a cover portion of the shaft, a strainer 2i, and a control valve mechacasing the pumping elements may be removed nism 25. It is contemplated that the shaft 22 and replaced without disturbing pipe connecwill be connected by suitable means to a driving tions or the driving connection to the pump motor (not shown), that an inlet port 26 will motor, and more particularly to provide such a be connected to a source of fluid supply, and a unit with either single stage or two-stage pumpdischarge port 21 to a burner nozzle. The casing ing lem nts, parts are formed to provide a substantially cylin- Another object is to provide such a fuel pump drical chamber or recess 28 in which the pumping with pumping elements assembled in a. unitary device 2i and strainer 24 are positioned for purdevice so that they may be secured together and poses hereinafter more fully described. removed as a unit. As illustrated herein, the casing part is in 20 Another object is to provide a fuel pumping the form of a body member which is also used 20 unit with a drive shaft extending from one end for supporting the fuel unit. Preferably this and a removable cover on the other, and strainer member is formed with supporting lugs 29 havand pumping elements wlthdrawable when the ing bolt receiving apertures (Fig. 4). The cover is removed without disturbing the drive part 20' is in the form of a closure or cover and 25 shaft and its seal mechanism. is bolted to the part 20 by means of a plurality 25 Further objects include the provisions of a of screw devices 3i. Thus, if the unit is mounted pumping unit permitting change of the pumping with the surface 29' of the lugs against a suitable elements without disturbing the pipe connections, bracket or other support, a suitable motor may drive shaft, mechanical seal or drive motor, and be connected to the shaft 22 and the necessary are interchangeable and readily located in the part 20 to provide a permanent installation. As housing. hereinafter more fully described, the internal Other objects will become readily apparent parts of the unit may thereafter be removed for from the following detailed description taken in inspection, repair or replacement without disconnection with the accompanying drawings, in turbing the driving motor or pipe connections, 35

so in which single and two-stage pump assemblies pipe connections made to the ports in the casing which: merely by removing the cover part 20'.

Fig. 1 is a plan view of a preferred form of In the form illustrated in Figs. '1 to 6 and 12, the invention. the pumping device 2| comprises a toothed roller Fig. 2 is an elevation looking at the left hand or drive element 32, an internally toothed eleend of Fig. 1. ment or ring 33, a crescent guard member 34, Fig. 3 is a vertical central section substantially and a housing for these elements consisting of along the line 3-3 of Fig. 1. circular members or end plates 35 and 36 and Figs. 4, 5 and 6 are sections respectively alongan intermediate annular member 31. The housthe lines 44, 5-5, and 6-8 of Fig. 3. ing parts form a cylindrical pump chamber and Fig. 7 is a vertical central section through anare preferably secured together by means of a 45 other form of the invention. pair of screw devices 38 so that the pumping Figs. 8 to 11 are sections respectively along device may be pre-assembled as a unit before the lines 8-8 to .|l--ll of Fig. '7. insertion into the casing chamber 28. The guard Fig. 12 is a section along the line |2-l2 of 'member 34 is secured to the plate 36 by pins 34'. Fig, 3. The unit is secured in the casing against the end 50 While I have shown in the drawings and shall wall 28' of the cylindrical chamber 28 by means herein describe in detail a preferred embodiment of the plurality of screw devices 39 (Fig. 3) which of my invention, together with a modification extend through the end plates 35 and 36 and thereof, it is to be understood that .I do not intend the intermediate member 31 and into threadedto limit the invention to the specific forms disengagement with the casing part 20. In order 55 to facilitate locating the pumping unit in thecasing, it is preferably provided with a pair of pins 40 and corresponding bores 4| in the part for receiving the pins. The adjacent end of the drive shaft 22 extends into the chamber 28 and has a key-way 22' into which a key 42 on the roller 32 fits in driving relation when the pumping unit is secured in place.

Fluid is admitted to the casing chamber 28 by means of the inlet port 26 (Fig. 1) and passes through the strainer 24 before entering a pump inlet port 45 (Fig. 6) formed in the pump housing end plate 35. The strainer, as illustrated in the drawings, is made of suitable gauze and is cup-shaped, a channel-like ring 46 secured to the peripheral edge of the strainer being arranged to flt snugly over the outer surface of the end plate 36 ofthe pumping unit and up against the adjacent end wall 28' of thechamber 28. The strainer may be reenforced by means of a wire helix 24'.

After passing the pumping elements 32, 33, the fluid is discharged into an outlet recess 56 in the end plate 36 (Fig. 5) and through a port 5| (Figs. 4 and 5) which is formed in the casing part 20 and communicates with a valve chamber 52.

The valve mechanism designated generally as 25 is operable to control the discharge of fluid from the pumping unit and preferably functions only after the discharge pressure has attained a predetermined value. Should the discharge pressure exceed the predetermined value due to an obstruction in the discharge pipe or nozzle or for any other reason the valve ,mechanism is arranged to by-pass a portion of the fluid either to the source of supply or the casing chamber 28.

In the formsof the invention illustrated herein, the casing part 20 has a depending portion 53 provided with a transversely extending bore 54 (Fig. 4). The valve chamber 52 is formed in this bore between the adjacent ends of a bushing 55, which is screw-threaded into one end of the bore 54, and a sleeve member 56 which is pressed into the central portion of the bore 54. The bushing 55 contains the discharge port 21 which is formed in part by the hole in a leather or composition washer 51 secured in a recess in the inner end of the bushing 55. A hollow piston valve 58 is slidably mounted in the sleeve 56- so that the operative end 51 thereof will be subiected to the fluid in the valve chamber 52. This valve is held seated against the'washer 51 to close the discharge port 21 by means of a coiled spring 59 which is positioned within the hollow piston valve. A cap member 60 screw-threaded in the other end of the bore 54 carries a screw device 6|, the free end of which engages in a cup-shaped member 62 seated against the adjacent end of a coil spring 59 to provide for adjusting the pressure of the spring on the piston valve and thereby the fluid pressure at which the valve opens. Preferably, a removable closure 63 is threaded on the cap 60 so as to protect the adjusting device 6| and facilitate access thereto to permit inserting a screw driver to turn the screw device.

In order to by-pass excess fluid, the piston valve 58 is also arranged to uncover a by-pass port 65 which is formed in the sleeve 56 and communicates with an annular passage 66 formed around the sleeve 56 (Figs. 3 and 4). This annular passage communicates with a vertically extending port by-pass 61 (Fig. 3) which in turn communicates at its upper end with the casing chamber 28 to provide an internal by-pass, and

threaded portion 61' of the port 61 as shown in" Fig. "l, and the outer end 61" of the port is connected to the return pipe.

In order to insure quiet operation-of the pump, means is provided for completely filling the fluid conveying recesses in the roller and ring as they pass the crescent 34 at which time the fluid in the recesses is not under pressure. As illustrated in the drawings, this means includes a port 10 (Figs. 3 and 5) in the end plate 36, the port communicating with an arcuate chamber 1| in the end plate. The port 10 is located so as to communicate with the fluid carrying recesses 33 (Fig. 12) of the ring element as they pass over the guard 34. A recess 10' in the end plate 35 is positioned opposite the port 10 and communicates with the recesses 33 and also with recesses 32' in the roller 32 as they pass the guard 34, so that the recesses in the roller as well as those in the ring will be filled, if necessary. A thin wall or disk member 12 separates the arcuate chamber 1| from an opposed arcuate chamber 13 '(Figs. 3 and 4) formed in the casing part 20. This arcuate chamber communicates at its lower end with a passage 14 which connects with the annular passage 66. The wall 12 is preferably made of impregnated fabric or other suitable material so that the outer portions thereof may serve as a sealing gasket between the end plate 36 of the pump device and the end wall 28' of the chamber 28, and is provided with an overflow opening 15 above the level of the port 10 so that fluid from the arcuate chamber 13 may overflow into the arcuate chamber 1| and maintain the port 10 and recess 18' filled.

In operation, the fuel unit of Figs. 1 to 5 is arranged to function automatically when driven at the proper speed. When the pump is started, the piston valve 58 closes the discharge port 21 and is not operated to open said port until the pressure in the valve chamber 52 reaches a predetermined amount. Normally, the arcuate chamber 1| remains filled with fluid with the result that this fluid feeds through the port 18 to the passing recesses in the ring 33 and through recess 10' to the roller recesses 32. Thus, if any of these recesses are not completely filled with fluid, they are filled as they pass the port 10. Normally, these recesses are filled as they pass the inlet port 45 when the shaft 22 is rotated in a counterclockwise direction as viewed from the right hand end of Fig. 3. Preferably, an arcuate cavity 45' is formed in the plate 36 (Fig. 5) opposite the inlet port so as to facilitate the filling of the recesses in the pump elements. Fluid from the discharge port 50 of the pump passes downwardly through the passage 5| to the valve chamber 52 and builds up pressure in said chamber until it is suificient to operate the valve. It will be readily appearent that as soon as the pressure is sufflcient, the piston valve slides toward the left as shown in Fig. 4 and opens the discharge port 31. Should the pressure in chamber 52 rise still further, the piston valve slides sufilciently far to the left to uncover the by-pass port 65 and passes any excess fluid into the an- I3. If the upper end 81' of the by-pass port 51 is unblocked and the lower end 81' is plugged (as shown in Fig. 3) the by-passed fluid passes directly into the chamber 28.

Preferably, the piston valve 58 is provided with an annular recess 58' and a connecting side wall port 58" so as to relieve any pressure which may build up in the left hand end of the bore 54 and thus insure proper operation of the valve. Likewise, a leakage return port 88 is provided in the casing part 28 so as to supply fluid to a chamber 8| in which the mechanical seal 23 is located. A port 82 (Figs. 1 and 3) is provided in the upper portion of the casing part 20 for the reception of a vacuum gauge and a port 83 (Fig.2) is provided in the portion 53 forthe reception of a pressure gauge, the port 83 communicating at its inner end with the valve chamber 52.

The form of the invention illustrated in Figs. 7 to 11 is in many respects identical with that of Figs. 1 to 6 and 12, the differences residing wholly in the construction of the pumping unit and the strainer. The pumping unit of this form is a two-stage device and will now be describedin detail.

This pumping unit comprises end plates 35 and 86, an intermediate plate 85 and annular spacing members 86 and 81. A first stage pump comprising a roller 88 and an intermeshing toothed ring 89 are operable in the chamber formed intermediate the plates 35 and 85, and a second stage pump comprising a roller 88 and a toothed ring I88 operate in the chamber formed intermediate the plates 85 and 36. The rollers 88 and 98 are provided with driving pins IM and I82 respectively which interengage with a keyway I83 in a drive shaft ilitwhen the pumping unit is assembled.

A crescent I85 for the first stage pump is suitably secured to the plate 85, and a crescent I88 is secured to the end plate 36 for the second stage pump.

In this form of the invention, the end plate 35 (Figs. 7 and 11) contains an inlet port 45 for supplying fluid to the first stage pump, the intermediate plate 85 having an opposed arcuate cavity 45' (Fig. 10). A discharge port M8 for this pump is formed in the intermediate plate 85 (Fig. 10) and extends upwardly to connect with a port I II which extends through the member 81 and plate 36 so as to discharge into an annular recess H2 in the end plate 36. The second stage'pump is provided with fluid from this recess through an inlet port II3 (Fig. 9) formed in the end plate 36. Fluid discharged from the second stage pump passes through an outlet port I in the plate 36 and thence through a discharge port H5 in the end plate and a connecting port I I6 in the casing (Fig. 8) which communicates with the valve chamber 52.

The elements forming the first stage pump have a wider face as indicated in Fig. 7, so that an excess of fluid will be supplied to the second stage pump. The excess is permitted to overflow through the opening I5 in the partition wall 12 from whence it may pass downwardly through the passage I4 and annular passage 68 and into the vertical by-pass port 61. The parts 86, 85 and 81 of the two-stage pump are preferably located one on the other, and on the mounting plate 36 81, and part-way'into the holes in plate 36 in which the pins 48 are partly inserted.

A cup-shaped strainer I28 is provided in this form of the invention to surround the pumping unit. Preferably, the strainer has an outer side wall I2I and an inner side wall I22 joined by means of a channel-like annular member I23 which is spaced from the surrounding casing and pump parts, .as shown in Fig. 7 so as to permit fluid to flow therebetween and pass through the inner wall I22. The inner wall I22 is also provided with a'channel-like annular member I24 which fits snugly around the plate 35 to'provide a'support for the strainer. The fluid supply'pipe connected to the casing 28 discharges into the casing chamber 28 in the same manner as illustrated in Figs. 1 to 6 so that the fluid mustpass through the strainer before being admitted to the first stage pump.

In the form of the invention embodyin the two-stage pump, fluid also enters the recess 28 by means of an intake port 28 as shown in Figs. 1 and 2. .The fluid passing to the first stage inlet 45 passes through the strainer on its way. The first stage pump generally serves as a suction pump for drawing fluid through the intake pipe .to the chamber 28, through the strainer and into the inlet 45. The output from the first stage pump passes through the ports H and III (Figs. 10 and 11) and into the arcuate recess II2 (Fig. 9) from whence it passes to the inlet port II3 for the second stage pump. The excess fiuid from the first stage pump passes out through the overflow opening 15 and through arcuate recess I3, passage", recess 86 and into the by-pass port 61. The fluid discharged by the second stage pump chamber 52. The valve functions to control the discharge of fluid through the port 21 and the bypass of fluid to the port 61 and chamber I3 in the same manner-as set forth for the single stage unit of Figs. 1 to 6 and 12.

The casing of the unit is preferably built as shown to accommodate either a single stage pump or a two-stage pump. In this manner, the number of different parts used in constructing the two pumps is maintained at a minimum, the parts of the two-stage unit being identical with those of the single stage unit with the exception of the two-stage pump, the strainer, and the screws for securing the two-stage pump in the casing. In fact, parts of the two-stage pump are identical with those of the single stage pump, as, for example, the end plate 35 and the pumping elements of the first stage. drive shaft is used for the two forms of the invention, the end plate 35 of the single stage unit being centrally apertured to permit the, use of the longer shaft of the two-stage unit, as illustrated in Fi 3.

The preferred construction also provides for convenient replacement of the pumping means (or change of the unit from single to two-stage or vice versa) without disturbing the drive motor, the drive shaft or the mechanical seal, and also without disturbing the pipe connections. Thus. as will be readily apparent from Figs. 3 and 7, it is merely necessary to remove the closure 28' whereupon the strainer may be pulled out. Thereafter, by removing the bolts 39 (or r 39), the pumping means in each case may be removed as a unit by pulling it off the end of the drive shaft. This facilitates removal of the pumping units for cleaning and repairing or for replacement. It is also possible to remove the valve mechanism without disturbing the pipe connections by unscrewing the cap member and withdrawing the valve out toward the left, as shown in Figs. 4 and 8.

The preferred construction is such that the pump assemblies are readily interchangeable and are easily located by the pins 40.

The mechanical seal 23 in the particular form shown herein is the subject matter of a copending application Serial No. 179,168, filed December 10, 1937.

I claim as my invention:

1. A device of the character described comprising, in combination, a casing having a cylindrical recess in one end thereof, a shaft receiving bore extending through the other end thereof and a depending portion having a transversely extending bore for housing valve mechanism, a detachable closure for the recessed end of the casing, a drive shaft rotatably mounted in said shaft receiving bore having one and extending into said cylindrical recess and the other end projecting from the casing, a rotary pumping means positioned in said cylindrical recess and driven by said shaft and including a circular plate mounting member detachably secured. to the end wall of said recess, an intake port in said casing communicating with said cylindrical recess, an inlet port for the pumping means communicating with said cylindrical recess, an arcuate recess in said circular plate member in the face engaging the casing which communicates with said pumping means, an arcuate recess in the adjacent wall of the casing, means separating said recesses and having an aperture connecting upper portions of said recesses to provide an overflow opening, an outlet port for the pumping means connected to said valve housing bore, a bypass port from said valve housing bore back to said cylindrical recess, a port connecting the lower portion of the second arcuate recess with said bypass port, a discharge port, and valve means in said valve housing bore for controlling the flow of fluid through said bypass and discharge ports.

2. A device of the character described comprising, in combination, a casing having a cylindrical recess therein, a rotary pumping means positioned in said cylindrical recess, including a circular mounting member detachably secured to one end wall of said recess, an intake port in said casing communicating with said cylindrical recess, an arcuate recess in said circular mounting member in the face engaging the casing which communicates with said pumping means, an arcuate recess in the adjacent wall of the casing, means positioned between said mounting member and casing to separate said recesses and having an aperture connecting upper portions of said recesses to provide an overflow opening, a discharge passage for the device, valve means for controlling the flow of fluid through said dis-- charge passage, and means for diverting a portion of the fluid from the discharge passage to said second arcuate recess.

3. A device of the character described comprising, in combination, a unitary casing having a cylindrical recess in one end thereof, a shaft receiving bore extending through the other end thereof, a chamber for housing valve mechanism, an intake passage and a discharge passage, a detachable closure for the recessed end of the casing, a drive shaft rotatably mounted in said shaft receiving bore having one end extending into said cylindrical recess and the other end projecting from the casing, mechanical sealing means for the projecting end of said shaft, a rotary pumping means positioned in said cylindrical recess and removable therefrom as a unit comprising a mounting member secured detachably against the end wall of said recess and provided with a bore through which the shaft extends, an annular member positioned against said mounting member and forming the outer wall of a c'ylindrical pumping chamber, a plate member positioned against said annular member and cooperating with the mounting member and the annular member to form said cylindrical pumping chamber, a crescent-shaped guard secured to one of said members, a roller detachably splined to said shaft and positioned in said pumping chamber within said guard, an annular pumping member positioned in said pumping chamber externally of said guard, said pumping members having means to propel fluid through said chamber, means securing said plate member, said annular member and said mounting member together so as to be removable as a unit from the casing, a cup-shaped screen in said cylindrical recess intermediate said intake passage and the inlet to the pumping chamber and having its rim fitting snugly around said mounting member and against the end wall of said recess so as to be removable from the recess when said closure is detached, and valve mechanism in said valve chamber for controlling the flow of fluid through the discharge passage.

4. A device of the character described comprising, in combination, a unitary casing having a cylindrical recess in one end thereof, a shaft receivin bore extending through the other end thereof, a chamber for housing valve mechanism, and intake and discharge passages arnectible driven engagement with said shaft so as to be removable therefrom as a unit when said closure is removed and without disturbing said conduit connections or the connection to a drive motor comprising a mounting member se- I cured detachably against the end wall of said recess and provided with a bore through which the shaft extends, an annular member positioned against said mounting member and forming the outer wall of a cylindrical pumping chamber, a plate member positioned against said annular member and cooperating with the mounting member and the annular member to form said cylindrical pumping chamber, means including a member detachably splined to said shaft for propelling fluid through said pumping chamber, means securing said plate member, said annular member and said mounting member together so as to be removable as a unit from the casing,

a cup-shaped screen in said cylindrical recess mediate said intake passage and the inlet 'todetached, and valve mechanism in said valve chamber for controlling the flow of fluid through the discharge passage.

5. A device of the character described comprising, in combination, a unitary casing having a cylindrical recess in one end thereof, a shaft receiving bore extending through the other end thereof, a chamber for housing valve mechanism, and intake and discharge passages arranged at their outer ends for connection to external conduits, a detachable closure for the recessed end of the casing, a drive shaft totatably mounted in said shaft receiving bore having one end extending into saidcylindrical recess and theother end projecting from the casing for connection to a drive motor, mechanical sealing means for the projecting end of said shaft, a rotary pumping means positioned in said cylindrical recess, means for securing said pumping means detachably to the inner end wall of the casing and in disconnectible driven engagement with said shaft so as to be removable therefrom as a unit when said closure is removed and without disturbing said conduit connections or the connection of the shaft to a drive motor, a cupshaped screen in said cylindrical recess interthe pumping means and supported from said pumping means to be removable from the recess when said closure is detached, and valve mechanism in said valve chamber for controlling the flow of fluid through the discharge passage.

6. A device of the characterdescribed comprising, in combination, a casing having a re-- cess therein, a rotary pumping means positioned recess in the adjacent wall of the casing, means positioned between saidmounting member and casing to separate said last mentioned recesses and having .an aperture connecting upper portions of said recesses to provide an overflow opening, a discharge passage for the device, valve means for controlling the flow of fluid through said discharge passage, and means for diverting I a portion of the fluid from the discharge passage to said second recess.

7. A device of the character described comprising, in combination, a casing having a recess therein, a rotary pumping means positioned in said recess, including a mounting member detachably secured to one end wall of said recess, interengaging toothed members and a crescent guard between portions thereof, an intake port in said casing communicating with said recess, a recess in said mounting member in the face engaging the casing, means establishing communication between said last mentioned recess and said pumping members in the vicinity of said guard, a discharge passage for the device, valve means for controlling the flow of fluid through said discharge passage, and means for diverting a portion of the fluid from the discharge passage to said second mentioned recess.

8. A device of the character described comprising, in combination, a unitary casing having a recess in one end thereof, a shaft receiving bore extending through the other end thereof, a chamber for housing valve mechanism, and intake and discharge passages arranged at their outer ends for connection to external conduits, a detachable closure for the recessed end of the casing, a drive shaft rotatably mounted in said shaft receiving bore having one end extending into said recess and the other end projecting from the casing for connection'to a drive motor, a rotarypumping means positioned in said recess, means for securing said pumping means detachably in the casing and in disconnectible driven engagement with said shaft so as to be removable therefrom as a unit when said closure is removed and without disturbing said conduit connections or the connection of the shaft to a'drive motor comprising a mounting member secured detacha'bly against a wall of said recess and provided with a bore through which the shaft extends, an apertured member positioned against said mounting member and forming the outer wall of a pumping chamber, a plate member positioned against said apertured member and cooperating with the mounting member to form the pumping chamber, means including a member detachably splined to said shaft for propelling fluid through said pumping chamber, means securing said plate member, said apertured member and said mounting member together so as to be removable as a unit from the casing, a cup-shaped screen in said cylindrical recess intermediate said intake passage and the inlet to the pumping chamber and having its rim fitting snugly around said mounting member so as to be removable from the recess when said closure is detached, and valve mechanism in said valve chamber for controlling the flow of fluid through the discharge passage.

9. A rotary pump comprising, in combination, a casing having a first and a second part, a recess in one of said parts, the other of said parts forming a removable closure, a rotary pumping means positioned in said recess comprising a housing mounted on one of said parts and forming a pump chamber, interengaging toothed members positioned in said chamber and a crescent guard between portions thereof, said housing being provided with an intake port for the pump chamber, means forming an auxiliary chamber in said part on which said housing is mounted, a discharge passage for the pumping means, a passage for conducting a portion of the liquid discharged from the pumping means to the auxiliary chamber, and an auxiliary intake port for the pumping means communicating with said toothed members in the vicinity of said guard and connected to receive fluid from said auxiliary chamber to compensate for any deficiency of fluid in the spaces between the teeth of said members.

10. A device of the character described comprising, in combination, a casing having a first and a second part, one of said parts having a recess in one end thereof, a shaft receiving bore extending through the other end thereof, a chamber for housing valve mechanism, intake and discharge passages provided in said casing and arranged at their outer ends for connection to external conduits; the other part forming a detachable closure for the recessed end of the first part, a drive shaft 'rotatably mounted in said shaft receiving bore having one end extendtioned in said recess, means for securing said pumping means detachably to the inner end wall of one of said casing parts and in disconnectible said'intake passage and the inlet port to the pumping means and supported from said pumping means to be removable from the recess when said closure is detached, and valve mechanism in said valve chamber for controlling the flow of I fluid through the discharge passage.

' GUNNAR A. WAHLMARK. 

